Finding the Fourth Proportional to 1,087.31, 1,500.56 and 615.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.31 : 1,500.56 = 615.05 : x
2. Step 2: Convert to fraction form
   1,087.31/1,500.56 = 615.05/x
3. Step 3: Cross multiply
   1,087.31x = 1,500.56 × 615.05
4. Step 4: Simplify right side
   1,087.31x = 922,908.85
5. Step 5: Solve for x
   x = 922,908.85/1,087.31
6. Step 6: Final answer
   x = 848.80